The present invention relates to materials for one-piece golf balls and to core materials for solid golf balls such as two-piece golf balls and three-piece golf balls. More specifically, the invention relates to golf ball rubber compositions and golf balls having a good resilience and excellent durability.
To provide golf balls with an excellent rebound and a softer core, various improvements have been made in the polybutadiene formulations used as the base rubber. However, simply making the core softer compromises the durability of the ball to cracking with repeated impact.
To address this concern, JP-A 7-48477 describes a rubber composition for two-piece golf balls in which amide group-bearing microfibers or fine particles are used. JP-A 2003-180870 and JP-A 2003-210615 disclose the incorporation, within a rubber composition for a golf ball core, of an olefin resin and a rubber/polyolefin/polyamide (nylon) three-component complex.
However, even with these improvements, the golf ball core itself lacks sufficient durability.
The object of the invention is to provide golf ball rubber compositions of good resilience and excellent durability, and golf balls formed using such compositions.